A router is a physical or virtual internetworking device designed to receive, analyze, and forward data packets between computer networks. The router examines the destination IP address of a given data packet, and it uses headers and forwarding tables to decide the best way to transfer the packet. There are several types of routers, but most routers pass data between LANs (local area networks) and WANs (wide area networks). A LAN is a group of connected devices restricted to a specific geographic area. A LAN usually requires a single router.
Types of routers
Core routers are generally used by service providers (i.e. AT&T, Verizon, Vodafone) or cloud providers (i.e. Google, Amazon, Microsoft). They provide maximum bandwidth to connect additional routers or switches. Most small businesses will not need core routers. But very large enterprises that have many employees working in various buildings or locations may use core routers as part of their network architecture.
An edge router, also called a gateway router or just “gateway” for short, is a network’s outermost point of connection with external networks, including the Internet.
Edge routers are optimized for bandwidth and designed to connect to other routers to distribute data to end users. Edge routers don’t usually offer Wi-Fi or the ability to manage local networks fully. They typically have only Ethernet ports—an input to connect to the Internet and several outputs to connect additional routers.
Edge router and modem are somewhat interchangeable terms, though the latter term is no longer commonly used by manufacturers or IT professionals when referencing edge routers.
A distribution router, or interior router, receives data from the edge router (or gateway) via a wired connection and sends it on to end users, typically via Wi-Fi, though the router usually also includes physical (Ethernet) connections for connecting users or additional routers.
A wireless router is a device that performs the functions of a router and also includes the functions of a wireless access point. It is used to provide access to the Internet or a private computer network. Depending on the manufacturer and model, it can function in a wired local area network, in a wireless-only LAN, or in a mixed wired and wireless network.
vRouter is often used as a generic term for virtual routing, but it is also included in the name of several brand-name commercial products.
Virtual routing is a form of network functions virtualization (NFV), in which the functions of traditional hardware-based network appliances are converted to software that can be run on standard commercial off-the-shelf (COTS) hardware. This has the advantages of lowering hardware costs and allowing more hardware interoperability, rather than requiring a proprietary hardware platform.
Network topology with two routers using Hot Standby Router Protocol (HSRP) Source: Cisco
Because virtual routing liberates the IP routing function from specific hardware, routing functions can more freely move around a network or data center. In basic software routing function, routing software is added to the commodity server and that piece of hardware becomes a router. In a more sophisticated distributed routing environment, pieces of the routing software can be moved around entire networks while being managed by a centralized control plane.
This evolution means that routing functions can be dynamically configured or adapted to network needs. Open-source technologies such as OpenStack’s Neutron include ways for routing functionality to become software that is distributed through the network or data center.
How does a router work?
Consider a switch an air traffic regulator and information bundles as airplane went to various air terminals (or organizations). Similarly as each plane has a remarkable objective and follows a novel course, every bundle should be directed to its objective as productively as could really be expected. Similarly that an air traffic regulator guarantees that planes arrive at their objections without getting lost or experiencing a significant interruption en route, a switch guides information bundles to their objective IP address.
To coordinate bundles really, a switch utilizes an inside directing table — a rundown of ways to different organization objections. The switch peruses a bundle’s header to figure out where it is going, then counsels the directing table to sort out the most proficient way to that objective. It then, at that point, advances the bundle to the following organization in the way.
To dive more deeply into IP steering and the conventions that are utilized during this interaction, read What is directing?
What is the difference between a router and a modem?
Albeit some Internet specialist co-ops (ISPs) may join a switch and a modem inside a solitary gadget, they are not something similar. Each assumes an alternate however similarly significant part in associating organizations to one another and to the Internet.
A switch structures organizations and deals with the progression of information inside and between those organizations, while a modem interfaces those organizations to the Internet. Modems fashion an association with the Internet by changing over signals from an ISP into a computerized signal that can be deciphered by any associated gadget. A solitary gadget might plug into a modem to interface with the Internet; on the other hand, a switch can assist with conveying this sign to different gadgets inside a laid out network, permitting every one of them to all the while interface with the Internet.
Think about it like this: If Bob has a switch, however no modem, he will actually want to make a LAN and send information between the gadgets on that organization. In any case, he can not associate that organization to the Internet. Alice, then again, has a modem, yet no switch. She will actually want to interface a solitary gadget to the Internet (for instance, her work PC), yet can’t disperse that Internet association with different gadgets (say, her PC and her cell phone). Ditty, in the interim, has a switch and a modem. Utilizing the two gadgets, she can shape a LAN with her personal computer, tablet, and cell phone and interface them all to the Internet simultaneously.
What are some of the security challenges associated with routers?
Weakness takes advantage of: All equipment based switches accompany naturally introduced programming known as firmware that assists the switch with filling its roles. Like some other piece of programming, switch firmware frequently contains weaknesses that digital assailants can take advantage of (one model), and switch sellers intermittently issue updates to fix these weaknesses. Consequently, switch firmware should be refreshed routinely. Unpatched switches can be undermined by assailants, empowering them to screen traffic or utilize the switch as a component of a botnet.
DDoS assaults: Small and huge associations frequently are the objectives of conveyed forswearing of-administration (DDoS) assaults coordinated at their organization foundation. Absolute organization layer DDoS assaults can overpower switches or prompt them to crash, bringing about network personal time. Cloudflare Magic Transit is one answer for safeguarding switches and organizations from these sorts of DDoS assaults.
Managerial qualifications: All switches accompany a bunch of administrator certifications for filling regulatory roles. These accreditations are set to default values, for example, “administrator” as the username and “administrator” as the secret key. The username and secret word ought to be reset to something safer as quickly as time permits: aggressors know about the normal default values for these certifications and can utilize them to oversee the switch from a distance in the event that they are not reset.